docs(e911): replace unverified 'error tone' claim with status check guidance

Author: hey-august

fern/products/platform/pages/platform/phone-numbers/e911.mdx

@@ -103,6 +103,7 @@ dial 933 from it.
 it reads back the address on file for the number
 so you can confirm your registration is correct,
 and calling it never incurs the unregistered-call fee.
-If you hear an error tone instead of the address playback,
-provisioning hasn't finished yet —
-wait a little longer and try again.
+If 933 doesn't read back the address you registered,
+check the number's E911 status:
+provisioning may still be `pending`,
+or the number may not have an address assigned at all.